Video Codec Converter

Re-encode video to H.264, VP9, or AV1 entirely in your browser — nothing is uploaded

Before you start local encoding
  • Heavy on RAM and CPU: Both decoding and encoding run inside the browser. Videos above 1080p or larger than 500MB can spike memory usage enough to crash the tab or slow the device.
  • Speed depends on hardware acceleration: Without GPU acceleration the browser falls back to software encoding, which takes several times longer.
  • Your file never leaves the device: No video is uploaded to any server; every conversion happens locally.
  • Recommended environment: A Chromium-based browser with WebCodecs support (Chrome, Edge, Whale). Safari may not support encoding for every codec.
Drag a video file here, or click to choose one
MP4, WebM, MOV, MKV and more

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🎬 Video Codec Converter Guide

The EVEDAYS Video Codec Converter is a free tool that re-encodes video directly inside your browser without uploading it to a server. It drives your device's hardware encoder through the browser's WebCodecs API, so real transcoding happens with nothing to install. Use it when you want to: • Convert footage in an older codec to widely-playable H.264 • Shrink a video for the web using VP9 or AV1 • Reduce file size by lowering the resolution • Strip the audio track before sharing Supported codecs: • H.264 / AVC: The most broadly compatible option. Best when the video has to play everywhere. • VP9: Smaller files than H.264 at similar quality. A good fit for web delivery. • AV1: The best compression, but slow to encode and supported on fewer devices. Codecs your device cannot encode are disabled in the dropdown automatically, so you can see support before choosing.

📊 Codec comparison

H.264 / AVC (MP4 container) • Compatibility: Plays on virtually every device and browser. • Compression: The weakest of the three. • Encoding speed: Fastest, with the broadest hardware acceleration support. • Best for: Sharing when you don't know the recipient's setup — email attachments, messaging apps. VP9 (WebM container) • Compatibility: Chrome, Edge, Firefox, Android. May not open on older devices or in some editing software. • Compression: Roughly 30–50% smaller than H.264 at similar quality. • Encoding speed: Slower than H.264. • Best for: Background or demo videos hosted directly on a website. AV1 (WebM container) • Compatibility: Limited to recent browsers and devices. • Compression: The best of the three. • Encoding speed: The slowest. Long videos take considerable time. • Best for: When minimizing size matters most and you control the playback environment. Lowering the resolution shrinks the file substantially regardless of codec — going from 1080p to 720p more than halves the pixel count.

💡 FAQ

Q. Is my video uploaded to a server? A. No. Reading the file, encoding, and saving all happen inside the browser, and no network request is made during conversion. Q. Is there a file size limit? A. There is no fixed cap, but browser memory is the practical limit. Videos over 500MB may crash the tab, so consider lowering the resolution at the same time. Q. Some codecs in the list can't be selected. A. That means your device cannot encode them right now. The browser reports support through WebCodecs, and unsupported entries are disabled automatically. AV1 is the usual case. Q. Does it work on Safari or iPhone? A. Safari's WebCodecs support is narrower, so encoding may fail for some codecs. Chrome or Edge is recommended. Q. Will quality drop after conversion? A. Yes, slightly — this is a re-encode. Changing only the container without any quality loss is not offered. Q. Is the audio re-encoded too? A. Audio is copied through untouched whenever possible. It is only re-encoded when the target container cannot hold the original audio codec.